Safety electrical couplings



Aug. 25, 1942. A. E. HANsoN SAFETY ELECTRICAL COUPLINGS Filed 001'.. 2l, 194C 2 Sheets-Sheet l 2 Sheets-Sheet 2 /7/5 41' raR/ve x A. E. HANSON SAFETY ELECTRICAL COUPLINGS Filed Oct. 21, 1940 Aug. 25, 1942.

Patented Aug. 25, 1942 UNITED STATES PATENT OFFICE SAFETY ELECTRICAL COUPLINGS Anton E. Hanson, Chicago, Ill.

Application October 21, 1940, Serial No. 362,099

4 Claims.

This invention relates in general to safety electrical couplings, but more particularly it has reference to safety interchangeable interlocking electrical couplings, and one of the important objects of the invention is to provide a simple and effective safety coupling means for electrical fuse receptacles by which the electrical terminals thereof may readily be disconnectedly secured to the terminals of various kinds of electrical receptacles in such a manner as to insure against the danger of the fuse receptacle terminals and a variety of electrical receptacle terminals becoming disengaged from each other. And a further important object of the invention is to provide an additional safety feature in electrical fuse receptacles which provides for the insertion or renewal of fuses in the said receptacle without there being any danger to the person while performing this operation of being burned, or of there being formed any short circuits.

A further important object of the invention is to provide the safety coupling means to screw or lamp sockets, and Wall-plate receptacles or sockets, and to correlative screw sockets and plug receptacles.

And a further important object of the invention is to provide plug and socket receptacles with safety interlocking correlative coupling means.

These and other objects of the invention may be better understood from the illustrations in the accompanying drawings, and more fully described in the following specification, and more particularly pointed out in the appended claims.

In the several illustrations in the accompanying drawings- Figure 1 is a sectional View taken on the plane I I, of Fig. 2, and shows a fuse box in which the improvements of the invention are embodied;

Figure 2 is a sectional view taken on the plane 2 2, of Fig. 1;

Figure 3 is a sectional view taken on the plane 3 3, of Fig. 1;

Figure 4 is a sectional view taken on the plane 4 4, of Fig. 1,'

Figure 5 is a sectional view taken on the plane 5 5-, of Fig. 2;

Figure 6 is a part sectional View of the coupling means as applied to an electrical wall-plate receptacle and a sectional view of the coupling means as applied to an electrical screw or lamp socket;

Figure '7 is a sectional view showing an electrical plug and a socket receptacle being provided With the safety coupling means embodying the invention; and shows also, as in the lower portion of Figures 1 and 2, a method or means by Which the insulation of, in this case, a threewire electrical conductor may be securely fastened, as by clamping, in the receptacle abovementioned;

Figure 8 is an exterior view of an electrical screw-ended socket and a plug receptacle being provided with the safety coupling means embodying the invention; a portion of the coupling means being shown in section;

Figure 9 is an exterior view of an electrical plug and a socket receptacle being provided with the safety coupling means embodying the invention; a portion of the coupling means being shown in section;

Figure 10 is a sectional View taken on the plane I |0, of Fig. 8, of an electrical plug receptacle being provided with the safety coupling means embodying the invention, and shows the method by which the same may be securely locked to an electrical plate receptacle; and,

Figures l1 and 12 are exterior views showing the safety coupling means as embodying a form of the invention.

In the several illustrations similar characters refer to similar parts throughout the several views.

To further describe an important safety feature of the invention it may be here stated that the electrical fuse receptacle, designated by the reference character I9, is provided with an hinged closure Il, which is provided with an insulation plate Il. Upon the plate Il', is mounted electrical fuse clips 20, the lower ones being provided with resilient metallic contact terminals 2l, and the upper ones with similar contact terminals 23. The closure Il, being in its closed position the terminals, 2| and 23, frictionally engage, respectively, resilient metallic Contact terminals 22 and 24.

On opening the closure I l to the position indicated by dotted lines in Fig. 1, the terminals 2l and 23, become detached, respectively, from the terminals 22 and 24, causing the continuity of the electrical conductor disposed through the receptacle to be broken; and, on further opening of the closure Il, the electrical fuses, I9 and I9', may be removed and others inserted in the clips instead. Since the opening of the closure Il, causes the terminals 2| and 23, to become automatically detached from their respective terminals 22 and 24, thereby breaking the continuity of the said conductors which are disposed through the receptacle, would preclude any danger of a short circuit, or of a person being shocked, while removing or inserting fuses. From the above it may be readily understood that fuses, I9 and I9', may neither be removed from, nor replaced in, the clips 2t, until the closure II is fully opened and the circuit broken; therefore, the person performing this operation will be, as before stated, safe from any danger of being burned, shocked, or of causing a short circuit.

As a further and important safety feature of the invention it may be pointed out that correlative electrical fittings, or preferably termed receptacles, such, for instance, as a combined plug, socket, and fuse receptacle I0, a plug receptacle I3, a socket receptacle I3', an internally screw threaded or lamp socket I3", in which is screwed an incandescent lamp t3, a combined screw threaded plug and socket I3", and a plug receptacle I3, in which an incandescent lamp Q3', may be rigidly secured, and a plate or socket receptacle I5 (the receptacle Il), being provided, at its upper end, with plug-in terminals 3S and 39, and at its lower end 'with socket terminals 27) are each, with the exception of terminals 21, 35, and 39, provided with correlative interlocking annular segmental helical cam members such as, for instance, groove cams I6, and lug cams I'I. The cams, as here illustrated, could be considered as likened onto segmental portions of a two-pitch screw-thread; however, they could be of any other multi-pitch screw-thread.

rIhe upper end of receptacle I0, and the receptacles I3, I3, and I3", are each provided with a revoluble sleeve upon which is formed the said cam lugs Il. The revoluble sleeve I4, being designated for receptacle I0, while that of I2 is designated for receptacles I3, I3, and I3". The lower end of receptacle I, and the receptacles I3', I3, and plate receptacle I5, are each provided with groove cams I6, which are adapted to receive and cooperate with the cam lugs II, of a correlative tting or coupling in the manner of a screw-bolt and its associated nut on giving the same an axial twist, or until the correlative receptacles or couplings have become snugly engaged or attached to each other whereby to prevent the couplings from being separated through any undue longitudinal strain upon them.

The revoluble sleeve provides a very important feature of the invention in that it permits the attachment of correlative electrical receptacles,

such as those above-mentioned, to each other in the usual manner and then, therewith, clamping them together by means of the correlative interlocking cams as formed thereon and on the respective associated receptacle in the manner as described above.

Referring to Figure l, it will be noted that the closure II is hingedly secured at its lower end, as at 2S; being so hinged permits of the same being opened downwardly whereby to obtain better accessibility to the fuses, IS and I9, mounted thereon. The fuses, I9 and I9', being installed in their respective clips 2S, and the closure II being in its closed position, the terminals 2 I, and the terminals 22, which extend from socket terminals 21, become frictionally engaged to each other, and, as well, do the terminals 23, and the terminals 2d, which extend from, respectively, electrical conductors it and 152, which are, in turn, connected with, respectively, plug-in terminals 39, and with plug-in terminal 38, through the medium of conductor ring 31, form electrical conductors throughout the receptacle Ii).

Referring to sectional views Figures 1, 2, 5, and

l0, it will be seen that the lower portion of receptacle I3 is formed with rectangular walls 35, two opposite sides of which being inclined downwardly toward each other as 3S, so as to form opposing inclined planes against which a pair of clamping jaws, 34 and 34', which have corresponding inclined sides, operate toward each other to firmly grip the surface of the insulation covering, in this case, of a three-wire electrical conductor or cable 32, when being drawn `down by means of screws 33. Two of the wires, 29 and 3i, being the main conducting wires, While the third wire 30, forms a ground connection. The terminals 29 and 3l, being connected, respectively, to plug-in terminals 23 and 28, but the ground wire 30 is connected to the wall of the receptacle. It will be noted that the inner Wall of jaws, 313 and 34', have corrugations or bumps di, formed thereon which, when the jaws are forced, by means of the screws 33, into clamping position against the insulation, become imbedded into the insulation so as to more firmly grip the cable and prevent any danger of the same from being pulled out from the clamping jaws.

As will be noted in Figures 1 and 6, plate I5 may be fastened, as by means of screws 45, to a wall or Xed place I8.

Having thus described the invention it can be readily understood that the minor details of its construction may be altered without departing from the scope and spirit of the invention, and without losing any of its attendant advantages. rIherefore, what is claimed is desired to be secured by Letters Patent.

I claim:

l. In combination, a pair of interconnectable safety electrical couplings, one of the pair comprising a dual purpose electrical coupling, the said coupling providing a compartment having an hinged closure therefor, an insulation plate carried by the said closure on its inner side, the same having an arrangement of fuse clips mounted thereon, the said coupling being provided at one of itsends with a revoluble annular sleeve having annular helical cam lugsV disposed thereon, and having at its opposite end annular helical cam grooves disposed thereon, and one of the ends of said coupling comprising a plugin end, and the end opposite thereof comprising a plug-receiving end, the said plug-receiving end being adapted to be detachably interlocked to the other of said pair of electrical plug receptacles, the same having an annular revoluble sleeve revolubly secured at one of its ends, the said sleeve being provided with annular helical cam lugs, and the said receptacle having an Varrangement of annular helical cam grooves'disposed thereon at its other or oppositejend. Y

2. In combination, a pair of `interconnectable co-relative safety electrical couplings, one of the couplings thereof comprising a double-ended electrical coupling, one end thereof comprising a plug-in end and the other end thereofcomprising a plug receiving end, the said plugfinend of the coupling having an annular sleeve revolubly mounted thereon, the said sleeve being provided with annular helical cam lugs, and the said plug receiving end of the coupling being provided with annular helical cam grooves, and the other of said pair of couplings adapted to receive acplug coupling, the said plug coupling being provided lwith concentric helical cam grooves, the-.said

cam lugs `on said sleeve being adapted to beV removably secured into co-operative relation to the said cam grooves on the said other Vcoupling whereby to draw the said couplings toward each other and form rigidly interlocked electrical couplings.

3. The combination in a dual purpose interlocking electrical coupling, of an interlocking electrical coupling having a plug-in end, and a plug-receiving or socket end, one of the ends of the coupling having an annular revoluble sleeve disposed thereon, the said sleeve being provided with annular helical locking cams, the other or opposite end of the coupling having an arrangement of annular helical cam grooves disposed thereon, the said coupling providing a compartment having an hinged closure therefor, the said closure having an insulation plate secured thereto on its inner side upon which is securely mounted electrical fuse clips, and an arrangement of electrical conductors suitably disposed throughout the said coupling, the said conductors being adapted to be disconnected whereby to break the electrical circuit on opening the said closure for the purpose of renewal or exchange of fuses being mounted in said clips.

4. The combination in one of a pair of interconnectable safety electrical couplings comprising a dual purpose electrical coupling, the said coupling having at one of its ends an annular revolvable sleeve mounted thereon, the said sleeve having annular helical cam lugs disposed thereon, and the said coupling having a pair of screwoperated electrical cable clamping jaws slideably mounted therein at its other or opposite end, means provided in said coupling for grounding che of the wires of a three-wire electric cable being secured between the said jaws, and the said cam lugs being adapted to engage corresponding annular helical cam grooves being disposed on a corelative safety electrical coupling whereby to draw the two couplings into interlocked rigid engagement to each other.

ANTON E. HANSON. 

